1. Field of the Invention
The present invention relates to a camera to which a film magazine housing a film with sound recording belt can be loaded and in which photographing is done while sound is recorded in said sound recording belt.
2. Description of the Prior Art
Recently it has become common in the field of a motion picture camera using an 8 mm film to use a film of magazine-housed type which is easily loaded into a camera. Lately a film magazine has appeared which has a sound recording belt and is able to be easily loaded into a simultaneous sound recording camera in which photographing and sound recording can be done simultaneously. Said film magazine has such an arrangement that a sound recording opening is provided beside a conventional picture image recording opening in said film magazine, and a constant speed feeding of the film for sound recording is done and sound recording is done by a magnetic head on the sound recording belt which is formed by magnetic coating on the film. While such elements for sound recording as a film feeding capstan, a pinch roller, a magnetic head, a head pad, a film guide, etc. are placed at such position as corresponds to the sound recording opening of the magazine in the film chamber in such motion picture camera using said simultaneous sound recording film magazine, these elements need such structure that when the film magazine is loaded into a camera or unloaded therefrom, the capstan and the pinch roller are separated from each other and so are the magnetic head and head pad to make the insertion of film therebetween easy. Also while the camera is in operation after the film magazine is loaded, the capstan and the pinch roller come into pressure contact to advance the film, which is being pressure held thereby, with a constant speed. At the same time, the magnetic head and the head pad come in pressure contact with the film being held therebetween so that sound recording is done magnetically at the sound recording belt of the film. To this end, such structure is generally used that the capstan and the magnetic head are used as the sound recording means fixed at the film chamber and, at the same time, the pinch roller, the head pad, and film guide, etc. are made as movable means. Such movable means are made to pressure contact with or separate from the above mentioned sound recording means in association with the operation of loading of the film magazine into the camera and unloading of the same from the camera.
Further, such structure is required that out of said movable members, the pinch roller maintains such state so as to leave a slight gap between the capstan and itself even when the other parts, i.e., head pad etc. are pressure contacted with the above mentioned sound recording unit part, and is pressure contacted with the capstan in association with the release action for photographing in a camera, and is separated slightly from the capstan again at the same time the release is stopped. A first reason therefor is that since the capstan ordinarily has a fly wheel for facilitating the rotation, it keeps on rotating by inertia after the shutter release is stopped. Therefore unless the pinch roller is separated from the capstan at the same time as the release is stopped, the film is fed excessively. A second reason therefor is that since the kind of material of the pinch roller ordinarily resembles rubber, when it remains in pressure contact with the capstan for a long time it is deformed, which is apt to cause wow and flutter at the time of later reproduction, therefore it needs to be prevented.
The engagement and disengagement of the pinch roller with the capstan in association with the shutter release has been done conventionally by such set-up that a spring member is made to intervene between a shutter release linked member and a movable member having the above mentioned pinch roller. The spring member is made to be compressed or expanded by the shutter release operation, and the pinch roller is made to pressure contact with the capstan by said spring power. To this end, while the release operation of the camera is desired to be as light as possible as its very nature, in the simultaneous sound recording camera with the above mentioned set-up, heavier a release operation has to be used unavoidably compared to that in a camera for picture image recording only without sound recording.